It is not clear whether Safari truly distinguishes between
a soft and hard refresh. However, on MacOS, holding down the Option key
while clicking the refresh button (with a text balloon of "Reload the current page.")
appears to perform a hard refresh. Though the refresh button can be pressed with the Shift key also depressed, this combination appears to be a soft refresh in our testing. On Windows, much the same appears to be the case, with the Alt key taking the place of the Option key.